如何在Rails 3中选择今天生日快乐的用户

rails generate migration AddBirthdayToUsers birthday:date
rake db:migrate

class User < ActiveRecord::Base
  def birthday_today?
    self.birthday.month == Date.today.month && self.birthday.day == Date.today.day
  end
end

class UsersController < ApplicationController
  def birthday_users
    @users = User.where("extract(month from birthday) = ? AND extract(day from birthday) = ?", Date.today.month, Date.today.day)
  end
end

<% @users.each do |user| %>
  <p>Happy birthday, <%= user.name %>!</p>
<% end %>